Process relating to refractory substances.



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ROBERT TRIPMAGHER, OF SOHWEIDNITZ, GERMANY.

PROCESS RELATING TO REFRACTORY SUBSTANCEI E.

Specification of Letters Patent.

Patented Aug. 10, 1909.

' Application filed April 28, 1909. Serial No. 492,671.

To all whom it may concern:

Be it known that I, ROBERT T RIPMACHER, a subject of the German Emperor, and residing at Schweidnitz, Silesia, German Empire, have invented certain new and useful Improvements in ProcessesRelating to Refractory Substances, of which the following is a specification. I

It is well known that certain minerals, esperially those belonging to the spinel group, both natural and artificial, are refractory in a. high degree. One of these minerals which withstands particularly high temperatures is, for instance, chrome-iron ore (chromite), whose chemical formula is FeCrO This material has consequently long been employed in pieces for lining the sole of the hearth of many kinds of metallurgical furnaces and the like.

The reason why chrome-iron ore is not generally employed for other than the abovementioncd purpose is the difiiculty experienced in uniting or binding the particles of the pulverized mineral. For in practice it is necessary that the degree of cohesion should be sufficient to enable the material to withstand the pressing or other treatment in making blocks, bricks, or like shaped pieces, as also all the phases of the firing or baking process; and when once given a 'firm, solid form it must be capable of retaining such for a sufficient period of time-in industrial use.

Prior methods of overcoming the difficulty. such as the employment of artificial (21c. chemically manufactured) aluminium hydrate (Al (OH) as binding medium for the pulverized chrome-iron ore, have not proved satisfactory viewed from an economical standpoint; or the agents which it has been proposed to add to the disintegrated chrome-iron ore for the purpose ofbinding it have been found impractical, since owing to their nature and the percentage in which they have to be added they too greatly diminish the degree of refractoriness which constitutes the most valuable feature of the ore.

According to my invention I employ as bindingagcnt for the pulverized chromeiron ore materials which are for the most part removed again in the course of the treatment, and yet insure thorough cohesion in all stages of manufacture, and yield a final product which haslost little or nothing of the highly refractory character of the ore.

In making my new binding-agent I dissolve in molasses or a similar saccharine solution boric acid or a borate (6.9. borax),

together with-a small quantity of chromic acid or a chromate (e. g. potassium or so dlum chromate, or potassium or sodlum bi- -chromate), and very finely emulsify naphtha In practice I prefer first to dissolve the boric acid in hot water, to obtain a concentrated solution, as it is but difiicultly soluble in cold water; to this solution I add the chromic acid; and then I mingle the m0- lasses. Hereupon I add the naphtha and thoroughly stir to insure uniform distribution. This results in the naphtha distributing itself in a state of-extraordinarily fine emulsion. Apparently this is due to the percentage ofalkaline constituents of the molasses. VVith the liquid so obtained. the pulverized chrome ores can be bound, pressed in the ordinary manner, dried, and tired at a sufficiently high temperature. The product retains its coherence. in all phases of the drying and firing operations as there is al-wa s a bindin constituent present.

The part played-by the chromic acid is an extremely peculiar and wholly unexpected one. Itnvill be found that-the briqnets or blocks formed when a binding-liquid containing chromic acid is used, stiffen after a short time (a few hours) in such manner that they can be shaped by hand without the employment of hydraulic presses. ,They

can then be pressed at once in the ordinary manner without any danger of their falling to pieces. In fact this subsequent pressing may even be omitted, or for instance only employed when it is desired say to stamp the manufacturers name or to render the edges of the blocks sharper. A particular advantage of this method is that blocks of othcr shape than the usual bricks can be readily manufactured, since the high pressure otherwise requisite is unnecessary and all danger of the blocks cracking or collaps inn is avoided. ("hromic acid, therefore. in

l hen a refractory material is required which will thoroughly resist the reducing; flame, which is not sufficiently the case with I chrome ores, there may be employed insteadof these some other refractory substance such as native orburnt magnesite, refractory clay, chamotte, or mixtures of these sub stances, bound by the new liquid. 7

Having thus described my invention, 1 declare that WhatAI claim is- 1. The process of binding refractory substances, consisting in treating the same in pulverized condition with a liquid which Econsists of a saccharine solution, and a chromiumcompound, in which naphtha is emulsified, substantially as described.

2. The process of binding refractory substances, consisting in treatingthe same in pulverized condition witha liquid which consists of a saccharine solution and. it"llioronand a chromium compound, in which naplltha is emulsified, substantially, as described. 3. The zprocess of binding refractorysub stancesl'consistiug in'treating the same in pulverized condition with a liquid which consistsflif a saccharinesolution, and-a chro- 3 mium compound, in which naphtha is einuls'ified, with the addition of a fiuorid, substantially as described. p v e. The process ofbindiug refractory suly stances, consisting imag n the same in pulverized condition with a liqllld which consists of a saccharine solution, and chromiaf acid, in which naphtha is emulsified, sub:- stantially as described.- v f 5. The process of binding refractory substances, consisting in treating lthe same in, pulverized condition with liquid which consists of a saccharine solution',-an( l bor I and chroniic acid, in which naphthais emul sified, substantially 'as described. a v

In testimony whereof I afliir my in presence of two witnesses.

ROBERT TRIPMAQHER,

Witnesses: I

Smormnn LUSTIG, EnNs'r KAl'rz. 

